Telephone-exchange system.



L. H. JOHNSON. TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED JUNE 7, l9l5.

v Patented Apr. 10, 1917.

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LEWIS HOWES JOHNSON, OF BLOOIVIFIELD, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN- MENTS, 1'0 WESTERN ELEOTBIG COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Specification Patented Apr, TO, 191?.

e ters Patent.

To all whom it may concern:

Be it known that I, LEWIS Howns JOHN-A son, a citizen of the United States, residing at Bloomfield, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Telephone- Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to such systems of the central energy type.

An object of this invention is to provide improved means for accurately ascertaining the number of calls which an operator answers. v

Tn accordance withthis invention, there is provided at a central oflice a registering device common to an operators position which is operated when the answering end of a link circuit is connected with a calling telephone line. Means are also provided for disconnecting the registering device from the link circuit immediately upon the operation thereof, in order that the registering device may thereafter be free for operation in connection with another link circuit. Means are also provided in association with each link circuit for causing the operation of the registering device whenever a connected subscriber makes a recall.

For a more complete understanding of this invention, reference is made to the accompanying drawing showing one embodiment thereof and wherein all apparatus .is shown in. its normal and unactuated condition.

In the drawing there is shown the usual subscribers stations, A and B, terminating at a central ottice at which is located a cord circuit C for interconnecting the stations. Subscriber A, wishing to converse with subscriber B, signals the operator in the usual manner. The operator, answering, inserts the answering plug into a jack of the calling line, causing the operation of supervisory relay 1 included in bridge of the talking strands of the cord circuit. Relay 1, in operating, causes the operation of listening relay 2 which connects the operators telephone set acrcss the talking strands of the cord circuit. The circuit for listening relay 2 may be traced from battery 3 through contact 4: of relay 5, lower winding of listen ing relay 2, contact 6 of relay 7, contact 8 of supervisory relay 1 and supervisory lamp 9 to ground. The operation of the listening relay 2 causes the operation of relay assoclated with an electromagnetic registermg device 16. The circuit of relay 15 may be traced from battery 17, through both windings of relay 15, contact 18 of listening relay 2, contact 19 of relay 5, contact 20 and right-handwinding of relay 21, contact 22 of relay 7, sleeve contacts of the answering plug and jack, and the winding of cutoff relay 28 to ground. The actuation of relay 15 causes the electromagnetic registering device 16 to register the call which the operator has answered. The registering device, in operating, short-circuits one winding of relay 15, thereupon permitting suflicient current to traverse the winding of relay 21 to actuate it. Belay 21, in operating. opens the hereinbefore traced circuit for relay 15 and completes a locking circuit for itself which may be traced from. battery 24 through contact 25 and left-hand winding of relay 21, contact 22 of relay 7, sleeve con tacts of the answering plug and jack, and the winding of c'utoif relay,23 to ground; llt is to be noted here that the electromagnetic registering device 16 and its associated relay 15 are common to an operators position, and therefore, when the circuit of re lay 15 is opened at contact 20 of relay 21', the registering device is disconnected from cord circuit C, and is thereafter free to be associated with and operated by another coild circuit when it is usedin answering a ca a The operator finding tha-t subscriber A desires to be connected to subscriber B, inserts the calling plug of the cord circuit into the jack of Bs line, thereupon operating relay 5 and cutoff relay 33. Relay 5, in operating, releases the listening relay 2, lights the calling supervisory lamp 26 and operates relay 27. The operation of relay 27 connects a source of ringing current 28 to Bs line to operate the signal receiving device at station B. Relays 29 and 30 c0- operate, in a manner well understood, with relay 27 in controlling the disconnection of the source of ringing current 28 from Bs line upon the removal of the receiver from the switchhook at station B. When the ring.- ing current has been removed from the all called line, calling supervisory relay 35 -operates to efi'ace the calling supervisory. lamp 26. w

At the conclusion of the conversation, subscribers A and B restore their receivers to the switchhooks, whereupon supervisory lamps 9 and 26 light to furnish disconnect signals. When 'As receiver is restored to the switchhook, supervisory relay 1, controlling supervisory signal 9, releases, causing the operation of relay 7 over a circuit which may be traced from battery 3, through contact 36 of relay 5, contact 67 of key 38, contact 39 of relay 1, and the righthand winding of relay 7 to ground. Relay 7, in operating, completes a locking circuit for itself which may be traced from battery 3 through contact 36 of relay 5, contact40 of key 38, contact 41 and left-hand wlnding 2 -of relay 7 to ground. In operating, relay 7 opens contact 22 thereof permitting relay 21 to release, and it also closes contact 42 in the circuit of a source of current i3 and interrupter 44. Should subscr1ber A thereafter, before the cord' circuit C 1s disconnected from the jacks of lines A and B, desire to make another call, the removal of the receiver from the switchhook will cause the actuation of relay 1, whereupon supervisory lamp 9 will flash intermittently to furnish a recall signal to the operator. The operator, observing the flashing supervisory lamp, operates key 38 which actuates listening relay 2 to connect the operators telephone set across the talklng strands of the cord circuit. The operation of key 38 also releases relay 7 which .retires the recall signal and closes contacts 6 and 22 of relay 7. The circuit of listening relay 2 may be traced from battery 3 through contact 36 of relay 5, upper winding of listening relay 2, contact 45 of relay 35 and calling supervisory lamp 26 to ground. Ascertaining that subscriber A desires to be connected to another telephone line terminating at the central office, the operator removes the calling plug from the jack of Bs line and mserts it into the'jack of the line wanted by subscriber A- When the calling plug is removed from the jack of Bs line, relay 5 releases, opening the circuit for the upper winding of listening relay 2, but closing the hereinbefore traced circuit through the lower winding of this relay before breaking the circuit through the upper winding. Itelay 5, in releasing, also causes the operation of relay 15, whereupon the registerlng device 16 again counts, and in so doing, causes the operation of relay 21- which opens the circuit of. relay 15 and locks itself up over a path hereinbefore traced thereby disconnecting the registering device from the cord circuit. When the calling plug is inserted into the jack of the line wanted, the c1rcu1t through the lower winding of listemng resubscriber. By the use of a system embodying this invention, it will be seen that an accurate record may be kept of the total number of calls which an operator answers, and that it is not possible to pad the registering device.

What is claimed is:

1. In a telephone exchange system, subscribers lines terminating at a central office, a link circuit thereat for interconnecting said lines, an operators telephone set, a relay controlled from a connected substation and actuated when the answering end of said link circuit is connected to a calling line to telephonically connect said operators telephone set with the calling line, and a registering device at the central ofiice for recording the number of calls answered by an op erator, said registering device operating upon the actuation of said listening relay.

2. In a telephone exchange system, subscribers lines terminating at a central ofiice, a link circuit thereat for interconnecting said lines, an operators telephone set, a relay controlled from a connected substation and actuated when the answering end of said link circuit is connected to a calling line to telephonically connect said operators telephone set with the calling line, a registering device at the central ofiice for recording the number of calls answered by an operator, said registering device operating upon the actuation of said listening relay, and relay mechanism actuated upon the operation of said registering device to disconnect said registering device from said link circuit.

3. In a telephone exchange system, calling and called subscribers lines terminating at a central oflice, a link circuit thereat interconnecting said lines, recall signaling means associated with the answering end of said link circuit, means controlled by the restoration of the calling subscribers receiver to and a subseiiuent removal thereof from the switchhook or'causing the automatic 0 eration of said recall signaling means to urnish a signal to the operator, a registering device at the central ofiice, a relay controlled by said second named means for conditionin said registering device for operation, an electromagnetic mechanism controlled by the disconnection of the calling end ofsaid link circuit from the called line for causing the mamas operation of said conditioned registering device, whereby said device registers the reca 4:. In a telephone exchange system, calling and called subscribers lines terminating at a central office, a link circuit thereat interconnecting said lines, recall signaling means associated with the answering end of said link circuit, means controlled by the restoration of the calling subscribers receiver to and a subsequent removal thereof from the switchhook for causing the automatic operation of said recall signaling means to furnish a. signal to the operator, a registering device at the central oflice, a relay controlled by said second name'd means for conditioning said registering device for operation, and electromagnetic mechanism controlled by the disconnection of the calling end of said link circuit from the called line for causing the operation of said conditioned registering device, whereby said device registers the re call, the operation of said registering device causing the actuation of said relay to disconnect said registering device from said link circuit.

In witness whereof, hereunto subscribe my name this 3rd day of June A. D., 1915.

LEwis HOWES JOHNSON. 

